﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace PCS_Linh.lab01
{
    class Sum
    {
        public void run()
        {
            Console.WriteLine("Welcome to C#!");
            int n = Convert.ToInt32(Console.ReadLine());
            int s = 0;
            for (int i = 0; i <= n; i++)
            {
                s = s + i;
            }
            Console.WriteLine("Result is: {0}", s);
            Console.ReadLine();
        }
    }
}
